The invention relates to an outer-skin module of a vehicle door and to a vehicle door having such an outer-skin module.
In vehicle construction nowadays, vehicle doors are complex structural units which comprise numerous individual parts. Main constituent parts are normally a door bodyshell, outer paneling, which is fitted on the outside of the door bodyshell, inner paneling which is fitted on the inside of the door bodyshell, and numerous add-on parts arranged between the outer paneling and the inner paneling, for example an electric window regulator, a loudspeaker, a side-impact protection device, a locking mechanism for the vehicle door, or the like.
The prior art has already disclosed the practice of designing the outer paneling of the vehicle door in the form of an outer-skin module having an outer skin and having an installation frame which is connected to the outer skin and is intended for fastening the module on the door bodyshell. The outer skin is, for example, a sheet-metal shell made of aluminum and is crimped onto the installation frame at the periphery. The installation frame, which runs all the way around the periphery, ensures precise and reliable fastening of the outer skin on the door bodyshell, since direct fastening of the thin sheet-metal shell is technically problematic on account of the insubstantial sheet-metal thickness of usually approximately 1.2 mm.
The installation frame is usually an aluminum sheet having a sheet-metal thickness of approximately 1.5 mm to 2.0 mm and can be adhesively bonded or screwed to the door body shell.
However, it has been found that such an outer-skin module comprising the shell-shaped outer skin and the installation frame is a very unstable structure on account of the large surface area of the outer skin, and this gives rise to handling problems. Therefore, there is an increase for example, in the outlay required in painting the outer-skin module, since additional stabilizing measures are necessary. Furthermore, the installation frame is fairly complex to produce since the large dimensions mean that the sheet-metal portion which is to be removed from the interior of the installation frame cannot be stamped out in a single procedure step, and therefore has to be removed in a number of steps.
In addition, attempts are being made, in general, to reduce the weight of the vehicle door and to simplify the complex construction of the same.
It is the object of the invention to create a stable outer-skin module which is straightforward to produce, as well as a vehicle door having such an outer-skin module, the vehicle door being straightforward in design and having the lowest weight possible.
This and other objects are achieved according to the invention by an outer-skin module of a vehicle door, having a side-impact beam for strengthening the vehicle door, having a shell-shaped outer skin, which has a shell periphery, and having an installation frame which runs all the way around the periphery, is connected to the shell periphery of the outer skin and is intended for fastening the outer skin on a bodyshell of the vehicle door. The installation frame and the side-impact beam are designed in the form of a single-piece module component.
Integrating the installation frame and the side-impact beam to form a single-piece module component renders the outer-skin module considerably more stable. In addition, there is no longer any need for any separate procedure step in order for the side-impact beam, which is usually provided in any case, to be fastened, in the form of an additional, individual component, on the door bodyshell. Instead, the installation of the side-impact beam now takes place together with the installation of the outer-skin module, in a joint procedure step.
Moreover, the increased inherent rigidity of the outer-skin module provided by the integrated side-impact beam provides for easier transportation and a lower level of outlay required in painting the outer-skin module.
In one embodiment of the outer-skin module, the installation frame of the module component has a frame portion which is adjacent to a window opening of the vehicle door, wherein, along said frame portion, the module component has a waist-rail reinforcement, which is formed-on in one piece and is intended for stabilizing the outer skin module. This waist-rail reinforcement advantageously results in the outer-skin module being further stabilized, and this further improves, for example, the handling of the outer-skin module during transportation or painting. Furthermore, it is usually the case that a waist-rail reinforcement is provided for stabilizing the outer-skin module even in conventional vehicle doors, but this waist-rail reinforcement is designed in the form of a separate component. Integrating the waist-rail reinforcement in a single-piece module component therefore reduces the number of individual components and therefore the installation-related outlay of the vehicle door.
The single-piece module component is preferably a shaped sheet-metal stamped part, in particular made of an aluminum sheet having a sheet-metal thickness of approximately 1.5 mm to 2.0 mm. Proceeding from a conventional installation frame, the side-impact beam and the optionally provided waist-rail reinforcement reduce the dimensions of the sheet-metal portions which are to be stamped out from the interior of the installation frame, and this reduces the complexity of producing the single-piece module component in relation to a conventional installation frame.
The side-impact beam is preferably arranged in the interior of the installation frame and extends more or less linearly between two essentially opposite points of the installation frame. In particular, the side-impact beam extends in a longitudinal direction of the vehicle door, wherein the longitudinal direction of the vehicle door, in the installed state of the latter, corresponds to a longitudinal direction of the vehicle. As an additional scaling measure, attaching a cover panel can be a cost-effective way of modifying the rigidity of the side-impact beam. Particularly efficient passenger protection is thus ensured by the side-impact beam.
According to a further embodiment of the outer-skin module, the module component has at least one stiffening strut, which is formed on in one piece and extends, transversally to a longitudinal direction of the side-impact beam, from the side-impact beam to the installation frame. The stability of the outer-skin module of the vehicle door is advantageously increased by one or more such stiffening struts. In addition, there is a reduction in the dimensions of the sheet-metal portions which are to stamped out from the interior of the installation frame, and therefore the single-piece module component is easier to stamp out of a sheet-metal blank.
In particular, a surface area enclosed by the side-impact beam and the installation frame is subdivided by the at least one stiffening strut into approximately equally sized partial surface areas. These partial surface areas determine the size of the sheet-metal portions which are produced as waste during the stamping-out operation of the module component. The smaller the sheet-metal portions, the more likely is it that the module component can be stamped out in just a single procedure step.
The at least one stiffening strut is preferably connected, in particular adhesively bonded, to the outer skin, at least in part, between the side-impact beam and the installation frame. This means that the outer skin is fixed by the at least one stiffening strut and therefore prevented from buckling. These additional supports mean that it is no longer the entire surface area, but only a number of small partial surface areas, of the outer skin which are subjected to buckling stress, and it is therefore advantageously possible for the buckling strength, and thus the thickness of the outer skin to be reduced.
The shell-shaped outer skin is preferably a metal sheet, in particular an aluminum sheet, the sheet-metal thickness particularly preferably being less than 1 mm. It is possible for the sheet-metal thickness to be reduced in relation to a conventional outer skin, in particular, on account of the additional fixing of the outer skin on the side-impact beam, of the at least one optional stiffening strut and/or of the optional waist-rail reinforcement.
In order to increase the rigidity and strength of the outer-skin module further, it is possible for the shell-shaped outer skin to have its shell periphery welded, in particular laser-welded, to the installation frame all the way around. As an alternative, however, it is also contemplated for the shell periphery and the installation frame to be connected to one another by crimping and adhesive bonding all the way around.
In addition, the invention also covers a vehicle door having an above-described prefabricated outer-skin module and a door bodyshell, on which the prefabricated outer-skin module is fastened, wherein the outer-skin module, in particular the installation frame of the outer-skin module, is screwed to the door bodyshell. As a result of the installation frame being designed in the form of a module component with add-on parts integrated in a single piece, the screw connection means that the side-impact beam and the optional waist-rail reinforcement are also fastened on the door bodyshell at the same time as the shell-shaped outer skin, and this advantageously simplifies the assembly of the vehicle door. The assembly can be further simplified by off-tool or system-based fitting. As far as the off-tool referencing is concerned, it is also possible to provide for removal and attachment with repeated accuracy in the event of servicing, it therefore being possible to close the maintenance openings in the inner part of the door.
According to one embodiment of the vehicle door, the installation frame is adhesively bonded to the door bodyshell all the way around. While the screw connection between the outer-skin module and the door bodyshell ensures a firm and reliable connection, the adhesive bonding serves predominantly for sealing and sound-installation purposes.
The door bodyshell is preferably a plastic component, in particular fiber-reinforced plastic component. Such plastic components, along with a low weight, have a high strength and can be formed, and produced, with a low level of outlay by injection molding.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.